


Shattered Tile

by Everyday_Im_Preaching



Category: Gravity Falls
Genre: Anal Sex, Biting, M/M, Mating Cycles/In Heat, Rimming, Sexual Content, Smut, ass eating, heat - Freeform
Language: English
Status: Completed
Published: 2016-03-15
Updated: 2016-03-21
Packaged: 2018-05-26 21:00:38
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,389
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6255604
Author URL: https://archiveofourown.org/users/Everyday_Im_Preaching/pseuds/Everyday_Im_Preaching
Summary: <blockquote class="userstuff">
              <p>Bill forgot that 'heat' was a thing that all demons went through. Including himself. But is Dipper ready for such a big step between them?</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

  * For [RadioActivity](https://archiveofourown.org/users/RadioActivity/gifts).



Bill slammed his hands on to the rim of the porcelain sink staring at himself in the mirror. Blue, heatless fire dripped from his left eye and down his cheek.

“Of course.” He snarled at himself, pushing off the sink, wiping it away. “Of _course._ ” A warm heat was bubbling in his gut, spreading up through his chest at hurried pace. Normal demons had a system to their heats-- every ten years, prime numbers. But Bill... it was like his genetics were thrown into a randomizer. He slammed his hand against the bathroom wall and he felt the tile splinter. “Fuck, Pine Tree’s going to be pissed about that.” _Pine Tree._ His head shot up. He couldn’t let the human know about this, but if the boy got within range of him-- shit. He’d fuck him up straight til Sunday.

The door opened to the flat and Bill’s ears perked up out of habit. Soft footsteps crossed the carpeted living room. Inhaling, he caught the heady, woodsy smell of his consort, and he swore, throwing himself against the previously scarred wall. He clung to it like a lifeline. He definitely couldn’t open the door.

“Bill?” Dipper called out, and Bill gripped the cool wall, trying not to throw himself through the flimsy wood.

“Pine Tree.” His voice came out as weak croak, layered over in static. “Leave.”

  
“Leave? But I just got home.” Dipper told him, and he heard the couch let out an exhausted breath of air as Dipper threw his backpack on the couch. “Is something wrong? Have a side girlfriend hiding in there with you?”

“No!” Bill hissed. “You really need to leave, Pine Tree.”

“You sound sick.” Dipper responded, and the footsteps got closer to the bathroom door. Bill growled loudly, eyes dilating and teeth gnashing as the idea of sinking them into Dipper’s flesh rose to the front of his mind. “Bill, are you okay?”

“No, Sapling.” He managed out.

“Tell me.” Dipper demanded quietly. “Honesty, remember?” Bill swore.

“Look, I’m in heat.” Bill told him through the door, hearing the faint popping of Dipper’s knees on the other side. “And you aren’t helping.”

“Heat? Like...you need to have sex?”

“Yes, ‘like I need to have sex’.” Bill replied sarcastically.

“I _could_ help.” Dipper told him quietly. “I mean, we’re _pretty much_ tied together for life, right? All that’s left is…” Dipper swallowed. “...well, you know what’s left.” Bill groaned. The marking.

‘You aren’t ready.” Bill told him, banging his head against the wall. “I don’t want to hurt you.”

“And I don’t want you to hurt. Come on, how bad can it be?”

“You have a test tomorrow, right? An important one? Kiss that goodbye. You get to be stuck in this apartment with me riding your ass for the next three days.” He unconsciously began to peel off his shirt, the heat bringing a thin sheet of sweat to his skin. Tossing it aside, he began to work on his pants.

“It’s not _that_ big of a test.” Dipper reasoned. “And I’m ahead in my classes-- there’s no problem, really.”

“Fuck Pine Tree, you aren’t making this easy.”

“I’ll go get some gatorade from the fridge and put it by the bed.” Dipper told him, and he heard the human stand.

“No.”

“Bill, I want to help you.” Dipper told him.

“Dipper, I can’t. I can’t let you make that decision right now.” He huffed. “If you don’t leave now then it’s over. You’re stuck with me forever. Can you accept that kid?”

“Bill, I love you.”

“You’ll never see your family again in the afterlife.”

“I don’t care.” Dipper told him. “Is that you want to hear? Bill, I don’t care about going to heaven or Valhalla or whatever.”

“Knowing how fucked up the Pines are, and how greedy you are-- bet you’d do anything to get away from that family of yours.”

“You aren’t going to chase me away with some petty ass fight.” He heard fingers gently swipe down the door, then pressing against it. “I want this. I want you.”

“Go to the bedroom. Get undressed.” Bill panted out, ideas of Dipper naked swimming in his head. “Grab some protein bars. I don’t know. Fuck, I didn’t think that you’d…” he pressed his head back against the wall. “I don’t want to hurt you.”

“You won’t.” Dipper told him. “See you in the bedroom, big guy.”

“Fuck you.” BIll snarled, forcing himself to stand. Dipper was going to regret this. But he’d _told_ him, he wanted this. He did, right? He waited a good fifteen minutes, carefully listening to the quick, hurried movements of his consort. When he was sure that Dipper had went into the bedroom, he opened the door to the bathroom.

Bill took a deep breath, near-salivating at the smell of Dipper. His fumbling steps turned into long strides, but he kept his hands at his sides, clenched into painful fists. The door was open, and he looked in. Dipper was laying on his stomach on the bed, his hat placed neatly on the shelf above. Bill’s pupils were blown wide, and he let out an unearthly growl of static.

“Dipper.” He rumbled. The human opened his legs in response, and Bill’s good eye nearly rolled back in his head. In seconds, he was climbing on the bed, fitting himself between them, hoisting Dipper’s hips up even higher, diving his face between the soft flesh of his ass cheeks. Dipper gasped and Bill dove his tongue into the warm heat, stretching him with long licks as he worked his tongue in and out. The long, serpentine organ was perfect for the job, twisting over itself. Underneath him, Dipper was groaning and drooling on the bed.

“Bill.” he keened. Still slightly aware, Bill pulled away, panting.

“Why’d you go ass up, Pine Tree?” He asked, throwing his upper torso over Dipper’s arched back.

“B-because, I’ve read a bit about animals in heat. And a little more about demons in heat.”

“Then why’d you question me earlier?”

“It was a shock.” He whined as he felt Bill line up. “Facing down is a sign of submission, right?” Bill grunted, nuzzling Dipper’s neck. Dipper squeaked as he felt something touch his leg, cool and strong, wrapping around it. “What’s that?” Getting no response, he wiggled a bit, and received a snarl and Bill thrust into him without warning. Whatever was on his leg had friends that proceeded to wrap around his arms pinning him in place. Fangs scratched at his shoulder and the small dip in his shoulder.

There was no adjustment time--Bill was slamming their hips together in rough slaps, and Dipper could do nothing. He just had to assume that whatever the things holding him down were associated with Bill. He couldn’t even turn his head due to the triangle demon keeping his face in his neck, now kissing the flesh there and grunting happily as he roughly fucked the human.  Remarkably, the demon’s hands were rubbing up and down Dipper’s sides and if not for the painful sting of flesh on flesh, Dipper could almost believe he was trying to soothe him. One of the hands detached from his side and slid down Dipper’s chest to run over his lower stomach. Dipper let out a soft noise of encouragement and the hand went lower so to wrap around Dipper’s cock. Bill whispered something in his ear that Dipper couldn’t understand, frowning at the odd, staticky sentence. Whether it was due to the language barrier or the interference, Dipper didn’t know.

“Bow.” Bill growled, and Dipper recognized that word. Bill had said it before when they fucked, and Dipper whined, tugging at the restraints on his arms. The demon let out a soft trill, and they released him, letting Dipper thump all the way forward, before they pinned him again. More wet kisses were placed up and down his neck, and lips found his. Dipper let out a disgusted noise and the kiss went from loving to forceful, tongue jamming itself in-between the lips, Bill snarling. Dipper opened his mouth and let Bill do as he wished, slightly grossed out. He’d have to have a conversation with Bill about that when they spoke next.

Dipper let out a needy whine as Bill continued to jack him off, blubbering out noises of devotion and Bill ate them up and responded in snarls and growls, possessive and promising, letting Dipper know _exactly_ who was in charge of his pleasure.

“Love you. I love you.” Dipper managed out and Bill’s teeth grazed his clavicle.

“I love you too. More.” Bill responded, and Dipper gasped. Fangs, sharp and unforgiving, sank into the area around his clavicle. His eyes rolled back inside his head in pleasure and he groaned. Things he’d never even imagined rolled past his eyes, secrets, alternate futures, anything and everything that he could ever know-- and then it was over. He began to babble and grip at the sheets about the thing he’d just seen. Bill growled satisfyingly, digging the nails of his hand still on Dipper’s hip into the soft flesh.

 

_“One day I’ll mark you and show you the secrets of the universe.” Bill told him as they stared at the stars, an arm wrapped tightly around the human’s waist. “But only for a moment. And then, and only then, we can be together forever.” He passed a hand across the sky above them, and Dipper reached up, interlacing them. “But that means you’re mine, Pine Tree. No take-backsies, no chickening out. The day that happens, your soul is mine. If something happens to this physical form of yours, you won’t be able to move on. You’ll be stuck in the mindscape forever with me.”_

_“I can’t wait.” Dipper told him, bringing the demon’s hand to his mouth and kissing it. Bill let out a playful growl and rolled over on top of Dipper._

_“I love you.” Bill pressed their foreheads together. “I_ ** _love_** _you.”_

  
  



	2. Aftercare

**Notes for the Chapter:**

> This was requested, and I couldn't help myself from agreeing ;3;   
> So here's a cute, fluffy afterward.  
> Also, thanks to Radioactivity, who took time from her Rune Factory to look this over!
> 
> Hey I have a tumblr! Click [here](http://iggy-master-of-all.tumblr.com/) to stay updated!

Dipper let out a muffled groan as lips peppered kisses across his shoulders.

“You did good.” Bill told Dipper, kissing the nape of his neck. Dipper flapped a hand at him weakly. “I honestly wasn’t expecting you to agree.”

“Why wouldn’t I?” Dipper asked, turning his face so that his words were clearer. “I love you, Bill.” Bill let out a quiet snort, and gently ran his fingertips down his sides, counting every bruise and bite mark. 

“I love you too, Pine Tree.” Bill told him, voice soft. “You’ve made me a very happy demon.” He eyed the glowing mark on Dipper’s shoulder. “A  _ very  _ happy demon.” He reiterated. 

“I get it, you’re happy you get to molest me for eternity or whatever.” Dipper told him. “Can you get me an aspirin? I can’t even make a crappy comparison about how much my back hurts.”

“That bad?” Bill teased. He sat up and swung his legs over the side of the bed. “I’ll be right back. Don’t run off now.” Dipper casually flipped him off, and Bill laughed at him. “Such a charmer.”

 

The kitchen was bathed in that warm glow you could only get on Sunday mornings. Bill felt like a new man-er, demon, standing in it like a king surveying his kingdom. He rooted through the cabinet drawers, pulling out the small white and red bottle, humming to himself as he did so. Grabbing a bottle of water and the piece of leftover coffee cake from a few days ago, he marched back to the bedroom to find that Dipper had flipped over on to his back, and was inspecting himself in the mirror.

“Beautiful, isn’t it?” Bill asked softly.

“Is it going to glow like this all the time?” Dipper asked, running his fingers down it reverently. Bill watched as the fingertips grazed it and shuddered. 

“No.” Bill answered, handing him the items he’d gathered. “Only when we’re intimate.”

“I can’t turn it off and on?” Dipper joked, sitting up so he could take the aspirin. “I was hoping I could be a nightlight, or a glowstick so I didn’t have to turn the light on when I go to the bathroom at night.” Bill snorted. “Thanks, by the way.”

“You’re welcome.” Bill pulled his legs back up underneath him. 

“Not just for the aspirin or the cake.” He took a deep breath. “Thank you for letting me spend the rest of eternity with you.”

“I wouldn’t want to spend it with anyone else.” Bill replied. “I should be thanking you for giving up so much for me.” He crawled over to Dipper. “My own little sugar pine.” Dipper laughed at him, shaking his head.

“You know, comparing me to all the pine trees you know isn’t romantic. Sugar pines aren’t even small. Nor do they grow in New Jersey.”

“Mine is very small, and was grown in California.” Bill pointed out, and Dipper shut his mouth. “Just because he’s relocated doesn’t mean he forgets his roots.”

“You’re far too clever for your own good, do you know that too?” Dipper asked, and Bill cupped his chin. He kissed him gently, then released Dipper from his grip.

“I do know that.” Bill told him. “I also know that you’re far too bright for a human.” Dipper rolled his eyes. “When should we tell your sister?”

“Tell my sister what?”

“Well, we’re together forever. Mabel will want to know.” Bill played with the curls on Dipper’s forehead, trying to push them back. “You get to explain how you chose me over them and all.” Dipper punched his arm lightly, and Bill smiled. “Oh, I’m ecstatic. She won’t be.”

“Fuck you.” Dipper growled, and Bill waggled his eyebrows. “You’re such a jerk.” Dipper shook his head. “Guess you’re my jerk now.”

“Forever.” Bill reminded him. “I mark for keeps.” He hesitantly reached forward, fingers grazing the mark. 

“Bill, are you okay?” Dipper asked, tone suddenly concerned.

“I’m fine.” Bill said, voice thick, staring at the bright blue mark. 

“You look like you’re ready to cry.” Dipper told him. 

“It’s just hard to believe. All of this.” He placed a hand on Dipper’s leg, suddenly serious. “I will be good to you, Pine Tree. I promise.” Dipper smiled at him. 

“And I promise to be good to you.” 


End file.
